1. Field of the Invention
The subject invention relates to surgical apparatus for performing laparoscopic and endoscopic surgical procedures, and more particularly to apparatus having a resilient end portion which can be articulated in a patient's body during a surgical procedure.
2. Description of Related Art
In laparoscopic and endoscopic surgical procedures a small incision or puncture is made in the patient's body to provide access for a tube or a cannula device. Once extended into the patient's body, the cannula allows insertion of various surgical instruments such as scissors, dissectors or retractors to perform the surgery.
An example of an endoscopic surgical instrument is illustrated in U.S. Pat. No. 2,113,246 which issued to Wappler on Apr. 5, 1938. This patent discloses endoscopic forceps comprising an elongated conduit with jaws at the distal end thereof, a control rod in the conduit for controlling the operation of the jaws, and a control handle at the proximal end of the conduit which is operatively connected to the control rod. This surgical instrument is extremely limited in its application in that the angle of the conduit portion mounting the jaws cannot be adjusted in relation to the remaining portion of the conduit during a surgical procedure.
Improvements have been made in the art of surgical instruments to increase their range of operability. For example, U.S. Pat. No. 4,763,669 which issued to Jaeger on Aug. 16, 1988 discloses a microsurgery instrument with an adjustable angle of operation for obtaining cervical biopsies.
Similarly, U.S. Pat. No. 4,880,015 which issued to Nierman on Nov. 14, 1989 discloses a surgical device having an increased range of operability. In particular, this patent shows a biopsy forceps designed for use through a flexible fiberoptic bronchoscope. The biopsy forceps includes a handle connected to a thin elongated flexible shaft with a distal portion thereof hinged to the shaft. A grasping tool or biopsy forceps is attached to the distal hinged portion. Control wires extend from the handle to the distal end to the shaft for controlling the angular rotation of the distal portion of the instrument.
Of the references discussed above, none disclose a laparoscopic instrument for insertion into a body cavity through a cannula and adapted for a wide range of laparoscopic surgical applications. Further, these instruments are not provided with means for rotating the tool head about the longitudinal axis of the endoscopic portion of the instrument. Instead, a surgeon using either of these prior art instruments must physically rotate the entire instrument in order to change the rotational orientation of the distal end of the conduit or tube.
Shape memory alloys, such as those disclosed in U.S. Pat. No. 4,665,906 which issued to Jervis on May 19, 1987, have been employed to increase the range of operability of various medical instruments. For example, U.S. Pat. No. 3,620,212 which issued to Fannon et al. discloses an intrauterine contraceptive device formed of shape memory alloy, and U.S. Pat. No. 3,890,977 which issued to Wilson discloses a bendable catheter or cannula formed of shape memory alloy. These alloys may be deformed by an applied stress and then return toward an original unstressed shape or configuration when the stress is released.
In accordance with this principle, it has been found that the range of operability of an endoscopic surgical instrument, and in particular an articulating endoscopic surgical instrument may be greatly increased by forming the distal end of the endoscopic portion from a shape memory alloy.
Therefore, it is an object of the subject invention to provide an endoscopic surgical instrument having an articulating distal end which is formed from a shape memory alloy having elastic-like qualities.
It is another object of the subject invention to provide an endoscopic surgical instrument having a tool head which is independently moveable about two axes of rotation relative to the handle while the instrument is in use.
It is yet another object of the subject invention to provide a lightweight articulating endoscopic surgical instrument which provides a clearer line of sight for a surgeon during a surgical procedure.
It is still another object of the subject invention to provide an articulating endoscopic instrument in which a variety of different tool heads may be employed.
Another object of the subject invention to provide an articulating endoscopic instrument which may be used to perform electrocauterization during surgical procedures.
These and other objects of the subject invention will be made more apparent from the following description taken in conjunction with the accompanying drawings.